Pressure sensitive adhesives, and other high viscosity coating materials are typically received by the coating plant in the form of solid, tacky rubber-like blocks. A covering paper must be removed from these blocks and the blocks are then cut into smaller pieces manually by means of a hot knife. The smaller blocks are then put into a melt tank, usually consisting of a steam or oil jacketed, agitated vessel, in which the temperature of the material is raised to the melt point or above, and the material is converted into a high viscosity liquid. This high viscosity liquid is then pumped into a heated, agitated holding tank and from there to the coating machine.
The object of this invention is to reduce degradation of the material from prolonged heating, mechanical shearing and exposure to oxygen, while providing means for preparing packaged material for the usage vessel without handling labor and at a high rate.